Yes, two people have been working on a native theming engine for Syllable (Desktop), and one of the plans to get more applications on Syllable is to make it easy to write REBOL 3 apps.

Another subproject, that we created a year ago, is to have more standard open source programs, starting on Syllable Server. In the past year we have been using Syllable Server with X11, the ROX Desktop and many apps such as Firefox and Thunderbird exclusively for our own development and infrastructure. (I'm on it right now, and the websites pointed to in the article are running on it.) Sadly, this standard software is so complex that it's much more work to reach release quality, so we can't release this system yet: